Lepidopteran stemborers, mainly the African stemborer Busseola fusca Fuller and spotted stemborer Chilopartellus Swinhoe, are among the economically important pests of sorghum in Kenya. Identification of sources of resistance is valuable for the development of an integrated pest management strategy to minimize losses. This study evaluated 27 genotypes with artificial infestations (mostly for tolerance) in two different agroecological zones. Data on damage from leaf feeding, dead heart, exit holes, and stem tunnelling; plant height; days to 50% flowering; total grain yield; and hundred-grain mass were collected. Significant differences (P< 0.001) were observed in all the traits evaluated, except leaf damage, under infestation by C. partellus. Classification into different categories of resistance revealed genetic variation. Genotypes resistant/moderately resistant to both pests were as follows: ICSA 464>ICSB 464>ICSB 467>ICSA 472>ICSB 472>ICSA 473>ICSA 474>IESV 91131 DL>Macia. The relative contributions of the damage parameters to grain yield loss were partitioned into direct and indirect relationships by path coefficient analysis with grain yield as the resultant variable. The results revealed that damage from exit holes, dead heart, leaf feeding and stem tunnelling had a negative indirect effect on grain yield. The identified genotypes can be used to enhance resistance to both pests in susceptible cultivars that farmers prefer.

Outcrossing to wild or unrelated strains has been proposed as a counter to the negative effects of adaptation by domesticated animals to captive-breeding environments. However, for mass-reared insects intended for sterile insect technique release, outcrossing may reduce productivity in mass-rearing facilities. In this study, we characterized adaptation to mass-rearing in the Queensland fruit fly Bactrocera tryoni (Froggatt). The features of domesticated B. tryoni were similar to those of other domesticated tephritids: shortened preoviposition period, higher egg production and increased early survival. We also examined the practical use of outcrossing to improve mass-reared strains. The B. tryoni mass-reared strain was crossed with independent strains that had already been domesticated for a varying number of generations. Preoviposition period, egg production, survival and stress tolerance were measured in the resulting hybridized strains. The short preoviposition period of the mass-reared strain was retained in outcrossed flies, indicating a genetically dominant trait. Egg production in outcrossed flies exceeded the mid-parent value, indicating some hybrid vigour for this trait. If both parents exhibited high egg production, the egg production of outcrossed strains was as high as that of the mass-reared strain. The high early survival of domesticated tephritids was reduced in outcrossed females, but not in outcrossed males. Preliminary thermal stress tests revealed that outbred flies were more stress resistant than the mass-reared strain. Therefore, the anticipated loss of productivity in outcrossed B. tryoni mass-reared strains is avoidable by choosing suitable parental strains and the outcrossed flies should have improved field performance. Using already domesticated strains should also facilitate the annual renewal of hybrid strains.

It i.s difficult to compare genotypic resistance to insects across seasons and locations because of the variation in the onset and severity of insect infestation. Therefore, in this study, we used the no-choice cage technique and detached leaf and artificial diet incorporation assays for evaluating chickpea genotypes for resistance to the beet armyworm Spodopteraexigua (Hubner). The results indicated that the no-choice cage technique was not useful for evaluating chickpea genotypes for resistance to S. exigua. In the detached leaf assay, leaf feeding by S. exigua larvae was significantly lower in ICC 12 475 and RIL 20 genotypes at the vegetative stage and in ICC 10 393, ICC 12 475, KAK 2, RIL 20 and RIL 25 genotypes at the flowering stage, while larval weight gain was lower in insects reared on EC 583264, ICC 10 393, ICC 12 475 and RIL 20 genotypes at the vegetative stage; and in those reared on ICC 10 393, ICC 12 475, EC 583264, ICCL 86 111, KAK 2, RIL 20 and RIL 25 genotypes at the flowering stage in plants raised under greenhouse conditions. In plants raised under field conditions, the EC 583260, ICC 12 475, ICCL 86 111, ICCV 10, KAK 2, RIL 20 and RIL 25 genotypes in the November sowing and the KAK 2, ICC 3137, ICCL 86 111 and RIL 25 genotypes in the December sowing suffered low leaf damage at the vegetative stage; and EC 58 320, EC 583264, ICC 12 745 and RIL 25 genotypes in the November sowing and the EC 583264, ICC 3137, ICC 12 475, 1CCL 86 111, KAK 2, RIL 20 and RIL 25 genotypes in the December sowing suffered low leaf damage at the flowering stage, while low larval weights were recorded in insects reared on the ICC 12 475, EC 583264, ICCL 86 111 and RIL 25 genotypes at the flowering stage. In the diet incorporation assay, the survival of S. exigua larvae reared on diets with leaf powder of the ICC 12 475, ICC 10 393 and RIL 25 genotypes was significantly lower, while a significant reduction in larval weights was recorded in those reared on diets with leaf powder of the ICC 10 393, ICC 12 475, ICCL 86 111, KAK 2, RIL 25 and ICC 3137 genotypes. The fecundity of insects was also reduced in insects reared on diets with leaf powder of the RIL 25, RIL 20, ICCV 10, ICCL 86 111, ICC 12 475, ICC 3137, KAK 2 and ICC 10 393 genotypes. The results suggest that detached leaf assay could be used for large-scale screening of chickpea genotypes for resistance to S. exigua, while the diet incorporation assay could be used to gain additional information on the antibiosis mechanism of resistance to this insect.

The effect of vegetation cover (millet) on the efficacy and conidial persistence of Metarhizium acridum (Driver & Milner) J.F. Bisch., Rehner & Humber was evaluated in semi-field conditions using breeding cages (2 × 2 × 1 m). A mixed population of third- and fourth-instar desert locust larvae, Schistocerca gregaria Forsskål, was used as a target. The insects were exposed in two different vegetation cover types classified as low (about 10%) and high (about 90%). Metarhizium acridum was used at a dose of 2.5 × 1012 conidia/ha in two different application volumes: 1 and 2 l/ha. Untreated insects kept in contact with treated vegetation were monitored to evaluate the persistence of conidia. The results showed that vegetation cover did not significantly (F= 1.320; P= 0.334) affect the efficacy of M. acridum. Under the high vegetation cover, the increase in the applied volume rate to 2 l/ha significantly improved the speed of mortality. Conidia persisted 6 days after treatment with a remarkable effect on untreated larvae exposed to the treated vegetation. In addition, the results of this study showed the efficacy of M. acridum in the low vegetation cover. With an important mass of vegetation, M. acridum conidia could persist even under high temperature conditions.

In the present study, experiments were carried out in French bean fields over two planting periods to evaluate the potential use of sticky traps for monitoring the populations of pest thrips. To this end, blue, yellow and clear sticky traps (with and without a thrips lure, i.e. Lurem-TR) were tested. Field observations on thrips catches were made at weekly intervals from the sticky traps, and absolute estimates of thrips populations and their natural enemies were made by destructive (picking leaves and flowers) and non-destructive sampling (plant tapping) of plants until crop senescence during the two planting periods. Blue traps caught two and three times more thrips compared with yellow traps over the first and second planting periods, respectively. Blue traps were more attractive to Megalurothrips sjostedti (Trybom), Frankliniella schultzei (Trybom) and Frankliniella occidentalis (Pergande), while yellow traps were only attractive to Hydatothrips adolfifriderici (Karny) and the natural enemies of thrips. The addition of Lurem-TR to the sticky traps significantly increased the capture of all thrips species, but not their natural enemies. The estimates of thrips populations from blue sticky traps with Lurem-TR were found to be highly correlated (r= 0.95; P< 0.001) with the absolute estimates of thrips using the destructive sampling method. The results demonstrate that blue sticky traps and Lurem-TR can be an efficient tool for the monitoring of thrips populations on French beans with least influence on their natural enemies.

The larval haemolymph of three cyclorrhaphous dipteran flies, Sarcophaga ruficornis Fab., Musca domestica L. and Chrysomya megacephala Fab., possesses five different types of haemocytes: prohaemocytes; plasmatocytes; granulocytes; spherulocytes; oenocytoids. In addition, vermicytes are found in the haemolymph of S.ruficornis and adipohaemocytes in the haemolymph of M. domestica. The total haemocyte counts in the three dipteran flies show an increasing trend throughout the larval stage, attaining a peak value in the freshly formed white puparium stage and declining thereafter. The differential haemocyte count shows a decline in the number of prohaemocytes with an increase in the number of plasmatocytes, granulocytes and spherulocytes.

The use of pheromones to disrupt mating behaviours is perhaps the most promising method for controlling the sugarcane pest Dasylepida ishigakiensis Niijima et Kinoshita, also known as the white grub beetle. Herein, based on laboratory observations of mating, oviposition and hatching behaviours in the white grub beetle, we suggest guidelines for the timing and length of sex-pheromone release in the field. In the present study, we collected virgin female adults early in the mating season (4 February) in sugarcane fields in Okinawa, Japan and mated them in the laboratory after different time intervals with males collected at the same time. We investigated the effects of delayed mating on mating success, timing of oviposition, female longevity after mating and progeny hatchability. Mating success – defined as the proportion of mated females that produced progeny – and hatchability were not significantly affected by mating delays of less than 31 days, although further delays dramatically decreased these parameters. Female life span and the time between mating and oviposition were unaffected by mating delay. Similar results were obtained for laboratory-reared adults mated on day 45, 60 or 80 after adult emergence. Based on these findings, we propose that releasing synthetic sex pheromones between mid-January (i.e. shortly before the start of the mating season) and late March would be optimal for disrupting the mating behaviours of this beetle in the field.

In this study, new methods to improve the mass production of the Philippines fruit fly Bactrocera philippinensis Drew & Hancock were assessed. A new adult screen cage equipped with perforated egging tubes was designed. The replacement of sweet potato with sugarcane bagasse, rice straw or powdered corn as an alternative bulking agent in the standard artificial larval diet was found to lead to positive results in large-scale rearing. Rearing protocols and product quality control procedures for egg incubation, sieving of pupae and pupal holding were examined. The adoption of these new rearing procedures at low cost was found to increase the production of the Philippines fruit fly in a mass-rearing facility without reducing the fitness of the insect.

Coptotermes heimi (Wasmann) is a termite widely present throughout Pakistan and causes detrimental effects in standing trees. In this study, the feeding preferences of C. heimi for 18 different wood species were determined through choice and no-choice trials under laboratory and field conditions. In no-choice laboratory trials, different combinations of wood blocks were used to determine wood consumption by C. heimi. Weight loss, consumption/individual and survival rate were evaluated. Populus euramericana was found to be the most susceptible wood species and Syzygium cumini the most resistant one. Nine different wood combinations were used under choice laboratory conditions; maximum feeding was recorded in P. euramericana and Pinus roxburghii (50.8–24.5 mg). However, minimum feeding was recorded in S. cumini (2 mg) and Tectona grandis (14.9 mg). Under no-choice field conditions, minimum feeding was recorded in S. cumini (9.5 mg) and maximum feeding in P. euramericana (60.5 mg). Under choice field conditions, maximum (58 mg) feeding was recorded in P. euramericana and minimum feeding in S. cumini. Feeding preferences in descending order based on wood consumption as a quantitative parameter documented were as follows: P. euramericana>Ailanthus excelsa>Azadirachta indica>P. roxburghii>Butea monosperma>Morus alba>Bauhinia variegata>Albizia lebbeck>Dalbergia sissoo>Heterophragma adenophyllum>Erythrina suberosa>Cassia fistula>T. grandis>Mangifera indica>Eucalyptus camaldulensis>Jacaranda mimosifolia>Bambusa bamboo>S. cumini.

The effectiveness of maize (Zea mays L.) planted at different times in a maize–cucumber intercrop to reduce the density of cucumber insect pests was investigated in 2007 and 2008. The cucumber varieties Marketmore and Hybrid F1 were established from seed as a monocrop or intercropped with maize, and with maize established 2 weeks before cucumber (2WBC), the same day with cucumber (SDC) or 2 weeks after cucumber (2WAC). Irrespective of the cucumber variety, there was a significant reduction (over 50%) in the density of insect pests in the cucumber–maize intercrop compared with cucumber alone. Similarly, in both years, fruit damage was significantly lower (about 50%) in the intercropped cucumber, particularly at 2WBC and SDC, compared with cucumber alone. Cucumber fruit yield was significantly higher at SDC but significantly lower at 2WBC relative to the other times. In both years, a relatively higher yield for cucumber was obtained at SDC than at 2WBC and 2WAC. Therefore, a significant control of cucumber insect pests and a higher cucumber yield were obtained when cucumber and maize were planted on the same day.

Increasing anthropogenic disturbance in tropical rainforests is a major challenge to biodiversity conservation. The responses of herbivorous insect communities to habitat changes are not well understood. In this study, we investigated the resilience of galling insect communities associated with Neoboutonia macrocalyx (Euphorbiaceae) trees to logging in Kibale National Park, Uganda. Resilience was measured by comparing the species density, abundance and community structure of gallers in nine differently aged successional forests with those in adjacent primary forests. Insect galls were sampled from the canopy of 10 randomly selected trees in each successional stage, five times in a 10-month period. A total of 7219 individuals representing five galler species were recorded. No significant differences were found in the species density and overall density of gallers between the regenerating and primary forests. The mean tree height was positively correlated with the overall density of gallers. The community structure of gallers differed significantly among the successional stages, but exhibited no clear directional recovery trend. In addition, remarkable seasonal variations were observed in galler communities, with peak abundance being found in the wettest months. The results of the preset study indicate that specialist galling insects whose hosts are pioneer trees can recolonize successional sites rapidly and are resilient to the effects of selective and clear-cut logging in case primary or secondary forests with an established population of Neoboutonia host trees (source populations) are close by. Thus, recovering tropical forests can provide important habitats for galling insect biodiversity, highlighting the need to include them in management and conservation priority plans.

To evaluate the effect of the carpenter bee, Xylocopa olivacea Lepeletier 1841, on the pod and seed yields of Phaseolus coccineus L., in this study, its foraging and pollination activities were examined in Ngaoundéré during the June–July 2010 and July–August 2011 cropping seasons. Treatments included open floral access to all visitors, bagging of flowers to avoid all visits and floral access to limited visits of X. olivacea. Observations were made on 120 flowers per treatment. In addition, all flower visitors were recorded. The seasonal rhythm of the activity of the carpenter bee, its foraging behaviour on flowers and its pollination efficiency (fruiting rate, number of seeds/pod and percentage of normal or well-developed seeds) were recorded. Phaseolus coccineus flowers were visited by 13 insect species in 2010 and by 14 insect species in 2011. Xylocopa olivacea was the most frequent visitor and intensely and exclusively foraged the flowers for nectar. The mean foraging speed was 9.28 flowers/min. In 2010, the foraging activity of X. olivacea resulted in a significant increase in the fruiting rate (27.49%), number of seeds/pod (45.43%) and percentage of normal seeds (89.38%). In 2011, the corresponding values were 56.14% (fruiting rate), 74.44% (number of seeds/pod) and 66.44% (percentage of normal seeds). These results reveal that this crop experiences a pollination deficit, considering that flowers visited by X. olivacea had higher yields than those under unlimited access to all visitors. Hence, the conservation of X. olivacea nests close to P. coccineus crop fields is recommended for improving pod and seed production.

In this study, a liquid larval diet as an artificial rearing medium was successfully tested for the Philippines fruit fly Bactrocera philippinensis Drew & Hancock. The biological parameters studied were pupal weight, adult emergence and fliers, sex ratio, fecundity and fertility. The insects performed most satisfactorily if corn (maize) oil was added to the liquid medium. Compared with the standard sponge ‘Kalle’ cloth, three locally available absorbent materials showed promise as a support matrix for feeding larvae.

This study was conducted in the Knuckles Forest Region in central Sri Lanka, and investigated how termite species richness, abundance and functional group diversity vary in different montane forest types and identified the likely causes of this pattern. Termite diversity declined with increased elevation, with upper montane forests recording a single endemic species, Postelectrotermes militaris Desneux. Transect sampling in lower montane forests yielded 26 species, with a higher number from dry forests (22 species) than from wet forests (15 species). Species specificity also was high in dry forests (11 species) compared with wet forests (four species). Termite abundance did not show a distinct trend in dry and wet forests. Live-wood termites were present only in upper montane and high-altitude lower montane dry forests. Wet forests had a higher relative abundance (78%) but not species richness (40%) of soil and soil–wood interface feeders. In dry forests, both species richness (82%) and abundance (88%) of fungus-growing wood feeders were higher. The study suggests that key drivers of the species distribution pattern are low temperature and differing forest floor conditions. In the upper montane forest floor where earthworms dominate, wet soil and damp, woody litter riddled with beetles are not favourable for termites. In lower montane wet forests, moist, thick decomposing leaf litter and in dry forests, drier, relatively undecomposed leaf litter with many dry sticks and branches support species with specific food habits.

Helopeltis theivora Waterhouse is a major sucking pest of tea in northeast India. No effective predators or parasitoids have been recorded from the field, and, therefore, insecticides play a significant role in the control of this pest. Potassium is known to impart physiological resistance to plants against sucking pests. The present study conducted two field trials to evaluate the bioefficacy of thiamethoxam 25 WG and bifenthrin 8 SC applied alone at the dosage recommended by the Tocklai Tea Research Institute and in combination with 2% potassium chloride (KCl) and mined potassium sulphate (K2SO4) against H. theivora. No phytotoxic effects were observed in the field when tea bushes were sprayed. The control of H. theivora achieved by the combinations of thiamethoxam+KCl/K2SO4 and bifenthrin+KCl/K2SO4 was found to be statistically significant (P< 0.05) compared with the sole application of the insecticides. These treatments could be included in the current integrated pest management programme against H. theivora.

Focal species are valuable tools for evaluating management practices for biodiversity conservation. Butterfly gardening through the creation of appropriate habitats can be a primary conservation tool to increase species abundance and richness and gene flow among the populations in fragmented landscapes. In this context, the role of butterfly gardens in the conservation of butterfly populations and the seasonal population trends of swallowtail butterflies (family Papilionidae) sighted in the Butterfly Safari Park at Thenmala were studied. A total of 4760 sightings of 15 species of swallowtails belonging to five genera were recorded, of which six were endemic species, three species had protected status and two were rare species. It is worth noting that of the 19 species of the papilionids recorded in Kerala, as many as 15 species were recorded in Thenmala. Of the various species recorded, Troides minos, Pachliopta pandiyana, Pachliopta aristolochiae, Graphium agamemnon, Graphium sarpedon, Papilio polytes, Papilio clytia, Papilio demoleus and Papilio polymnestor comprised the resident populations, while species such as Atrophaneura hector, Papilio helenus, Papilio dravidarum, Papilio paris, Papilio liomedon and Graphium nomius were found only during certain seasons. The overall butterfly abundance was high from August to November. The butterfly populations exhibited a gradual decline in numbers from December onwards with the onset of dry seasons. The abundance of butterfly populations was low during March–April. The abundance of T. minos, P. pandiyana, P. polymnestor, P. paris, P. dravidarum, P. helenus, P. polytes and P. liomedon showed a significant negative correlation with monthly average temperature and a significant positive correlation with humidity.

A survey of entomopathogenic nematodes (EPNs) belonging to the families Steinernematidae and Heterorhabditidae was conducted in three municipalities on the Pacific coast of the State of Colima, México, to determine their occurrence and recovery frequency and predominant plant species in cultivated and non-cultivated habitats. Nineteen soil samples were collected: seven from non-cultivated habitats and 12 from habitats or areas cultivated mostly with fruit and grain crops and grasses. Of the 19 soil samples, 14 were positive for EPNs; the total prevalence was 73.7%. From the 14 positive soil samples, 12 steinernematid isolates (85.7%) and two heterorhabditid isolates (14.3%) were recovered. Irrespective of the locations, EPNs from the genus Steinernema were recovered from the three municipalities; EPNs from the genera Steinernema and Heterorhabditis were recovered from Armería and Ixtlahuacán. Only steinernematid isolates were recovered from non-cultivated habitats. Most of the isolates were recovered from cultivated habitats, and our results suggest that there is a higher prevalence of EPNs in cultivated soils.

The application of the sterile insect technique to fruit flies involves the mass-production of the pest insects using an artificial diet, irradiation during a narrow time window at the late pupal or early imaginal stage to inhibit reproduction without affecting reproductive capacity, and then release into the target area where the sterile insects compete reproductively with their wild counterparts. The timing of irradiation is important to enable the release of males that are sterile but of good quality and exhibit an acceptable sexual performance. In this study, we examined the pupal development of 12 tephritid (Diptera: Tephritidae) species: Anastrepha fraterculus (Wiedemann), A. ludens (Loew), A. obliqua (Macquart), A. serpentina (Wiedemann), Bactrocera cucurbitae (Coquillett), B. dorsalis (Hendel), B. invadens (Drew, Tsuruta & White), B. oleae (Rossi), B. philippinensis (Drew & Hancock), B. tryoni (Froggatt), B. zonata (Saunders) and Ceratitis capitata (Wiedemann). The insects were reared at various temperatures, in the laboratory (15–28 °C) and under fluctuating natural conditions (20–35 °C). The gradual colour changes of the insect eyes during metamorphosis were observed and photographed, measuring the specific eye colour parameters of each species and matching them with the colour scale of the Munsell Soil Color Charts. The duration of pupal development and the time to emergence in Anastrepha species were longer than those in C. capitata and Bactrocera species at all the holding temperatures. The data obtained can be used by mass-rearing facilities to manage pupal holding conditions and as indicators for optimizing the timing of irradiation.

To assess the impact of the carpenter bee, Xylocopa olivacea Fabricius 1787, on the pod and seed yields of Cajanus cajan (L.) Millsp. 1900, in this study, its foraging and pollinating activities were examined in Nkolbisson during two seasons (July 2008–January 2009 and June–December 2009). Observations were made on 180 inflorescences per treatment. The treatments included unlimited floral access to all visitors, bagging of flowers to prevent access to all visitors, and floral access to limited visits by X. olivacea only. In addition, information on all floral visitors was recorded. The carpenter bee's seasonal rhythm of activity, its foraging behaviour on flowers, its pollination efficiency, the fruiting rate (Fr) and the number of seeds per pod were recorded. Nineteen species of insects were recorded visiting the flowers of C. cajan.Chalicodoma cincta cincta was the most prominent one, followed by X. olivacea, Apismellifera adansonii, Megachile bituberculata and Xylocopa albiceps, and the bees were the most frequent floral visitors. Xylocopa olivacea mainly foraged for nectar and pollen and its foraging speed was 11.75 flowers/min. The Fr, the number of seeds/pod and the percentage of normal seeds of unprotected inflorescences were significantly higher than those of inflorescences protected from insects. The foraging activity of X. olivacea resulted in a significant increase in the Fr by 22.26%, as well as the number of seeds/pod by 34.98% and the percentage of normal seeds by 12.09% in the two study years. Placing X. olivacea nests close to C. cajan fields is recommended to increase pod and seed production in Cameroon.