Cosmopolites sordidus (Germar), commonly known as banana corm weevil, is an important economic pest in Asia that can cause severe yield loss depending upon the stage at which infestation occurs. In spite of its economic importance, little is known about the population structure of this pest in India. Random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) were used to characterize the population genetic structure of C. sordidus collected from five hot spot locations in India. Nineteen RAPD primers and five selective AFLP primer combinations generated 147 and 304 amplification products, respectively. UPGMA dendrograms generated with both marker systems failed to reveal populations clustered based on geographic distance, which was confirmed by the Mantel test, which did not show a strong correlation between genetic distance and geographic distance. Values of indices of genetic identity showed that the populations were closely related. Though the gene flow estimate (Nm) between the populations was 0.469, suggesting restricted gene flow, the populations are not genetically distinct. These observations suggest that the range expansion of this banana pest in India has taken place through transport of infested corms and plant material, resulting in genetically close populations that are geographically distinct. These results provide important information on the population structure of this pest in India, which will aid in designing suitable strategies for its control and management, especially with respect to insecticide resistance.

Hyposidra talaca (Walker) is a recent host range-expanded major insect pest of tea in Northeastern India. We studied the egg-laying pattern of H. talaca in tea plantations with an aim to take suitable measures to disrupt egg hatching and to manage the pest. Egg clutch distribution in different heights (0–8 m) of 49 shade trees of seven species was studied. Stems and foliage of a total of 400 tea plants growing close to the shade trees were also subjected to the survey. Female moths deposited eggs underneath the scales of shade tree bark, lichen cover and the root mantles of parasitic plants that are growing on all shade tree plants, except Melia azaderach L. The shade tree bark of M. azaderach and tea plants had no egg deposits. Overall, 1785 egg clutches, comprising 84–302 eggs/clutch (average 258 eggs), were located. An average of 45.77 ( ± 7.06 SD, range 0–183) egg clutches was found per tree. The mean number of egg clutches was high in Acacia lenticularis Buch.-Ham. (95.4 ± 24.78 SD, range 40–183), and was low in Lagerstroemia speciosa (L.) Pers. (23 ± 6.42 SD, range 4–46). Overall, the number of egg clutches reduced with the height of shade trees. This study suggests that the oviposition of H. talaca is typical for an outbreak species and that the management of shade trees, including the choice of species, has an important role in controlling the pest in tea plantations.

A participatory project was conducted with small-scale coffee growers from Quindío Department, Colombia. In 34 coffee lots in three municipalities, growers implemented an integrated management programme against the coffee berry borer (CBB) Hypothenemus hampei Ferrari, based on improved cultural harvesting and sanitation practices (to remove breeding habitats) and releases of exotic parasitoids. Growers released over 10 million Cephalonomia stephanoderis and 5 million Prorops nasuta (both Hymenoptera: Bethylidae) over 2 years. Populations of the CBB declined from a range of 7–14% infested berries (Quimbaya), 10–13% (Montenegro) and 15–48% (Buenavista) prior to the integrated pest management programme, to an average of 2.1 ± 0.2% infested berries in Químbaya, 3.5 ± 0.2% in Montenegro and 2.8 ± 2.1% in Buenavista, over the following 25 months. Damage to parchment coffee similarly declined during this period. Six months after the final release of parasitoids had been made, we found both parasitoid species established in all three municipalities. However, P. nasuta were recovered more frequently (in 71.4% of lots where they were previously released) compared with C. stephanoderis (recovered in 30.8% of release lots). Average parasitism rates remained low, i.e. 3.7% for P. nasuta and 2.9% for C. stephanoderis. This low rate was probably due to the frequent manual removal of mature berries containing developing parasitoid larvae. In addition, the entomopathogenic fungus Beauveria bassiana was observed on average on 9.5% adult CBB in Montenegro, compared with mean infection rates of 4.3 and 4.4% in Quimbaya and Buenavista, respectively. Cultural harvesting and sanitation is an important component of CBB control, although it may limit the impact of the pest's parasitoids.

Although pesticides provide benefits in our battle to control pests that destroy more than a third of all food, the use of pesticides also results in significant costs to public health and the environment. As many as 500,000 humans are poisoned annually by pesticides in the world; the United States alone reports about 45,000 human pesticide poisonings.

Pesticides have also caused many detrimental effects on agroecosystems and natural ecosystems. These include: (i) reducing and sometimes eliminating beneficial natural enemies that keep pest populations at low densities; (ii) increasing or decreasing reproduction in various animal populations; (iii) altering decomposition rates of soil organic matter; (iv) developing insecticide resistance in pests, which results in increased pesticide use and additional crop losses; and (v) eliminating honey bee and other bee populations in certain regions thus reducing crop yields and quality. Pesticides also have had major impacts on fish, bird and mammal populations.

Oils from the seeds of neem, Azadirachta indica A. Juss and from a brown pepper, Piper guineense Schum and Thonn afforded protection to cowpea seeds from Callosobruchus maculatus infestation beyond 3 months. Insecticida! efficacy was higher with Piper seed oil (PSO). At 24 hr after surface treating cowpea seeds with 2 and 3 ml/kg of PSO, bruchid mortality reached 100 %, but with neem seed oil (NSO), mortality was 65–100% at 3–5 days. Oviposition in control averaged 60.75 eggs, 49.5 eggs in NSO and 15.5 with PSO. Reproductive efficiency (RE) of PSO-treated females was nil, and very low (1.7 to 2%) with neem oil, but high in control confirming adverse ovicidal effects of both oils. Piper oil prevented emergence of F1 bruchids and neem oil prolonged their mean development period over the control. Neem oil reduced seed damage by 94.67%. Because Piper seeds are a condiment in some Nigerian dishes, and are also used therapeutically in many traditional diseases, there may be no toxicity. However, yield of PSO is much less than that of neem from an equal weight of seeds extracted with organic solvents.

The density responsiveness of larvae and adults of Cheilomenes lunata (Fabricius) preying on Aphis craccivora Koch was investigated under laboratory conditions where temperature and relative humidity were uncontrolled and fluctuated between 24–30°C and 43–90% respectively. The feeding rates of C. lunata were positively correlated with the population density of prey. The number of prey consumed daily by each predator stage tested, increased more steeply at lower, than at higher prey densities, exhibiting thus the Type II functional response. Fecundity of C. lunata females also increased to a plateau with increasing prey density.

In the present study, Y-tube olfactometric assays confirmed that volatiles from maize seedlings infested with Chilo partellus larvae were more attractive to the borer's larval endoparasitoid Cotesia flavipes, than volatiles from uninfested maize. Coupled gas chromatography-electroantennographic detector (GC-EAD) analysis of the volatiles from larvae-infested maize revealed six electrophysiologically active compounds on the antennae of the female parasitoid. These compounds were identified by GC-MS as (Z)-3-hexenyl acetate, linalool, (E)-4, 8-dimethyl-1, 3, 7-nonatriene, heptanal, (E)-β-ocimene and a C-5 aliphatic compound. (E)-4, 8-Dimethyl-1, 3, 7-nonatriene was present in EAG-detectable amounts in the volatiles of uninfested seedlings. In bioassays, a blend comprised of (Z)-3-hexenyl acetate, linalool, (E)-4, 8-dimethyl-1,3,7-nonatriene, (E)-β-ocimene and heptanal was significantly attractive to the parasitoid. Of the individual compounds, (Z)-3-hexenyl acetate was attractive at the doses tested while (E)-4,8-dimethyl-1,3,7-nonatriene and heptanal showed varying degree of attractiveness to the parasitoid at different doses. Linalool and (E)-β-ocimene were unattractive at the same doses. The significance of these results is discussed.

Hexane and acetone extracts of Trichilia connaroides leaves were evaluated for their biological activity against the Bihar hairy caterpillar Spilosoma obliqua Walker, a destructive pest of crop, medicinal and ornamental plants. Fresh caster (Ricinus communis) leaves treated with a range of concentrations (1–10%) of the extracts were offered to 2nd instars for 120 h, followed by untreated leaves until pupation. Acetone extracts exerted better growth-regulatory properties than hexane extracts, shown by morphogenic malformation and adverse effects on the insect's larval duration, pupal duration, adult emergence and fecundity.

Biology, morphometrics and analyses of non-specific esterases were carried out for populations of Bemisia tabaci (Gennadius) collected from leucaena [Leucaena leucocephala (Lam.) de Wit] in New Delhi, India and compared with those for cotton populations. The developmental periods of the egg, and the first to fourth instars of the leucaena populations were 6.7 ± 0.18, 4.2 ± 0.18, 3.8 ± 0.14, 3.0 ± 0.0 and 5.2 ± 0.18 days, respectively, with a total life-cycle duration of 22.9 ± 0.58 days; fecundity (62.60 ± 61.53 eggs per female) and longevity (male: 13.50 ± 0.12 days, female: 16.50 ± 0.12 days) were higher than those recorded for the cotton population, with a sex ratio (male:female) of 1:3.7 in cotton and 1:4 in leucaena. Morphometrics revealed significant differences in the length of egg, second, third and fourth instars (P < 0.05). Of the 62 measurements of the puparia analysed, 70% of those of the head, 44% of those of the thorax and 51% of those of the abdomen showed significant differences between the cotton and leucaena populations. Mapping of the host association of samples onto principal component ordination showed their significant separation according to host plants, with the first three principal components accounting for 66% of the total variation. The analysis of non-specific esterases showed two bands at Rm E0.18 and E0.23 in the cotton populations but not in the leucaena populations. So far, B. tabaci is known on leucaena only from Taiwan. The present study reports it as a new host record from India in addition to documenting the biology, morphometrics and esterases of this and a cotton population.

The oriental fruit fly Bactrocera dorsalis (Hendel) is a very serious pest of fruit trees, causing enormous economic losses globally. The present study examines the capability of an artificial neural network (ANN) with a Quasi-Newton (QN) algorithm to predict a fruit fly trap catch and compare the results with those of a traditional regression model. MATLAB 7.0 was used to develop ANN programming and the fortnightly measurement of 14 input variables (abiotic along with biotic variables) provided the database for analysing the ANN model. An input model using a total of 14 identified input nodes with a selected QN-ANN structure (14-25-20-1) gave an optimum result. In general, the present study showed that an ANN could be used to estimate fruit fly trap catch with enhanced accuracy (R2 = 0.92; root mean square error (RMSE) = 23.75; Nash–Sutcliffe efficiencies = 0.99) over traditional regression models (R2 = 0.76; RMSE = 30.28; Nash–Sutcliffe efficiencies = 0.76). This finding helps the region-specific fruit fly monitoring and management programmes that lack long-term historic data.

Ladybeetles are known beneficial insects, with a long history in augmentative and classical biological control. The ladybeetle Oenopia conglobata (L.) is a natural enemy of many herbivores, particularly aphids. The temperature-dependent development of O. conglobata was studied at six constant temperatures (22.5, 25, 27.5, 30, 32.5 and 35 °C) to understand its development rate and environmental constraints better. Linear and nonlinear (Lactin) models were fitted to the data. In the thermal range from 22.5 to 32.5 °C, the rate of development increased for all stages; 35 °C was lethal for all stages and no eggs hatched. The Tb and K values for the biological cycle (egg–adult) were 8.84 °C and 263.15 DD, respectively. Depending on the model, tmin values for the total development time of the coccinellid ranged from 8.45 to 8.82 °C. The nonlinear model of Lactin estimated the optimum and upper temperature thresholds for the total development time of the ladybeetle to be 33.2 and 35.0 °C, respectively. High R2 values and low residual sum of squares values revealed a good fit to the experimental data for total development and different developmental stages of O. conglobata. The results may contribute to the improvement of practical methods for mass rearing of O. conglobata.

The pod-sucking bug Clavigralla tomentosicollis Sta˚l is the most important insect pest associated with cowpea in Africa and Burkina Faso, which causes seed malformation and destruction. The nutritional quality and physical structure, which vary according to the development stage of the pods, could have an impact on the biology of the bug. This laboratory study carried out at Kamboinse´ research station in Burkina Faso aimed at evaluating the effect of rearing the bug on three different types (young pods without grains, pods in filling stage and mature pods) of cowpea var. KVx 396-4-5-2-D, on the biology of C. tomentosicollis. The bug larvae were also fed on pod shells alone and on grains alone to identify which part and which stage of the pod would be most appropriate for bug growth and development. A qualitative chemical analysis of the shells and the grains was conducted to determine the compounds that might have an impact on insect growth in relation to the pod development stage. The best performances of larva and adult growth were recorded when the larvae were fed on pods in the filling stage. Most larvae fed on young pods extended their development period and died before completing the development cycle. Mature pods were less suitable for larval growth. Chemical analysis revealed that, compared to pods in filling stage, both the shells and the grains of mature pods contained antitrypsin and cyanogenetic heterosids (only in grains), hence their toxicity against the insect. It is recommended that control measures should target the filling stage, which is most susceptible to the bug damage.

The demographic attributes of the parthenium beetle Zygogramma bicolorata Pallister were studied using Parthenium hysterophorus L. as food under different abiotic and biotic variables. Intrinsic and finite rates of increase were highest with the shortest mean generation and doubling times when Z. bicolorata was fed on inflorescences followed by the leaves and stems of P. hysterophorus. Temperature significantly affected the demographic parameters. The net reproductive rate was highest at 27 °C and lowest at 35 °C. Different photoperiodic exposures altered the demographic attributes of the beetles with long-day exposure (14L:10D) resulting in optimal values compared with other photoperiodic exposures. Continuous darkness (0L:24D) and continuous light (24L:0D) suboptimally affected the demographic attributes of the beetles. In response to the light of different wavelengths, the net reproductive rate, and intrinsic and finite rates of increase were significantly higher when the beetles were reared under a broad spectrum of white light followed by those under ~570 nm (yellow), ~475 nm (blue) and ~650 nm (red). Information gained in this study may be helpful in the mass multiplication of Z. bicolorata, and thereby strengthening the biocontrol of parthenium weed.

The variation in demographic parameters (namely survival and fecundity, intrinsic rate of natural increase pre-reproductive period and relative growth rate) was used to assess the resistance of cowpea landraces (namely B261-B, B383, B013-F, B339 and Blackeye, as a check) against cowpea aphid (Aphis craccivora Koch). The experiment was carried out from 18 March 2011 to 5 April 2011. The demographic parameters of A. craccivora differed significantly among varieties, supporting our prediction that cowpea landraces resistant to cowpea aphid would have a significant effect on the demographic parameters of the aphid. We recorded significantly lower survival, fecundity, intrinsic natural rate of increase and relative growth rate on the landraces B261-B and B383 compared with the other landraces. A significant delay in the pre-reproductive period was also found on B261-B and B383. The results showed that landraces B261-B and B383 have an increased level of resistance as shown by the extended pre-reproductive period and the reduction in population growth rate, survival and fecundity. This information will be used in the characterization of the landraces before being incorporated in the breeding programme in Botswana.

Life table studies of Earias vittella (Fabricius) on different hosts in the Insect Biotech Laboratory, Department of Entomology, Dr PDKV Akola, revealed that survival (lx) of immature stages of E. vittella on different hosts was 0.65 on okra, 0.56 on cotton, 0.54 on semi-synthetic diet and 0.51 on mesta. The net reproductive rate (Ro), at the end of each generation, of E. vittella was 81.91 on okra, 56.70 on cotton, 53.02 on semi-synthetic diet and 36.63 on mesta (Hibiscus cannabinus L.). The net reproductive rate (Ro) followed the same order as the survival rate (lx) on the different hosts. The innate capacity for increase in numbers (rm) ranged between 0.0888 and 0.1334 females/female/day. In descending order, the rm values on different hosts were okra (0.1334), cotton (0.1111), semi-synthetic diet (0.1029) and mesta (0.0888).

The biology, insect density-yield loss relationships, genotype reactions, and consumption and utilisation of food by the legume pod borer, Maruca vitrata (Fabricius) on pigeonpea (Cajanus cajan) and Adzuki bean (Phaseolus angularis) were studied. Post-embryonic development was completed in 20.2 to 22.6 days. Grain yield in plants infested with 2 and 4 larvae was the same as that in uninfested controls, while plants infested with 8 and 16 larvae suffered between 50–68% grain yield loss in pigeonpea and 61–71% in Adzuki bean. Food consumption by third instars was highest on ICPL 90011. This genotype had the lowest approximate digestibility (AD) and efficiency of conversion of ingested food (ECI). The significance of these results in relation to economic damage thresholds is discussed.

The effectiveness of rearing fruit flies (Diptera: Tephritidae) for parasitoid production and pest control need to be improved. In these studies, the effects of dietary protein ingredients on the biological parameters of the peach fruit fly Bactrocerazonata (Saunders) for parasitoid production were investigated. Among the various food ingredients, torula yeast and brewer's yeast were found to be more promising than Nu-Lure® and protein hydrolysate for rearing of B. zonata. To reduce the infestation of this pest in mango Mangifera indica L. orchards, biological control agents and the male annihilation technique were evaluated. Significantly fewer fruits were infested with fruit flies in the treated blocks compared with fruits in the untreated block. The field efficacy of the hymenopteran larval and pupal parasitoids Aganaspis (Trybliographa) daci (Weld) and Dirhinus giffardii Silvestri, respectively, plus the male annihilation technique in controlling fruit flies was significantly high than that of biological control agents and male annihilation as separate treatments. The release of parasitoids as agents of biological control can play a major role in the suppression of fruit fly populations and parasitoids also pose a minimal non-target risk. Furthermore, combining control tactics could be a very important aspect of an action plan for fruit fly population suppression.

The life history of Oplostomus haroldi (Witte), a recently reported pest of honeybee colonies in East Africa, was studied for the first time under laboratory conditions. Adult O. haroldi collected from beehives in the coastal part of Kenya were reared on a mixture of moist sterilized soil and cow dung. At 25 ± 2 °C, 50 ± 5% relative humidity and a 10 h light-14 h dark photoperiod, the laid eggs took 11.9 ± 1.3 days to hatch into a curved pear-shaped scarabaeiform larva with a well-developed head and thoracic legs. The first, second and third larval instars lasted 14.6 ± 2.6, 17.5 ± 2.4 and 34.6 ± 2.4 days, respectively. The pupal stage, which was marked by formation of a mud cocoon, lasted 31.1 ± 6.7 days with the adults surviving for 2–6 months under laboratory conditions, suggesting that the beetle is multivoltine. A detailed taxonomic description of the external morphology of the third instar larva is provided.

The stemborers Busseola fusca (Lepidoptera: Noctuidae) and Chilo partellus (Lepidoptera: Crambidae) are important pests of maize and sorghum in South Africa. A habitat management system for these pests is being developed in the Northern Province of South Africa. This management system is similar to the one used in eastern Africa, where host and non-host plants of stemborers are used to repel moths away from the main crop and attract them to highly attractive trap plants. To identify possible trap crops, a survey of wild host plants of stemborers was undertaken in the Northern Province of South Africa and several new host plants were recorded. As a possible trap crop for stemborers, various Napier grass (Pennisetum purpureum) varieties were evaluated for oviposition preference by Ch. partellus moths and subsequent larval survival on those varieties. Few larvae survived longer than 15 days after inoculation onto Napier grass plants. A survey was conducted of farming practices that would affect the adoption of habitat management strategies. The high usage of tractors for ploughing may have a negative effect on adoption of perennial intercrops in a habitat management system. The common practice of free grazing animals also reduced the fodder value and benefit of trap crops. The value of Napier grass does not only lie in its use as trap crop but also as a measure to limit soil erosion and as animal feed.

Various alkaloids from Adhatoda vasica (Acanthaceae) were found to be responsible for the antifertility and antifeedant activity of the extracts of the plant against insects. Among the major alkaloids vasicine, vasicinol and vasicinone severe antifertility effects were exhibited by vasicinol against Dysdercus skoenigii and Tribolium castaneum due to blocking of oocytes in the oviduct. Feeding deterrence was observed against Aulacophora foveicollis and Epilachna vijintioctopunctata at 0.05 and 0.1% levels of these compounds. These allelochemics appear to show a dual activity vis-à-vis a species specificity.