…air through spiracles so must come to the surface frequently and spend most of their time feeding on algae, bacteria and other microorganisms in the surface microlayer. Larvae develop through four stages, or instars, after which they metamorphose into pupae. As with the larvae, pupae must come to the surface frequently to breathe, which they do through a pair of respiratory trumpets. The pupal stage does not feed and after 2-3 days, the dorsal surface splits and an adult mosquito…
…scutel that resembles a half moon. Another distinguishing characteristic is the presence of two horn-like lateral projections in the prothorax. Eggs are initially yellow and become pink when close to eclosion. Upon emergence, nymphs measure approximately 1 mm and bear a yellowish color. As they develop, they become greenish or gray. Females lay eggs on leaves, in batches of 5-7. First instars remain on eggs and undergo the first ecdisis shortly after they start feeding. From the third instar on,…
The red flour beetle (Tribolium castaneum) is an important pest of stored grains and agricultural produce world wide. Originating in the Asia-Pacific region, global food transportation has held re-distribute this pest globally, ensuring its place as one of the most important pest species of stored produce. Both the adult beetle and its larvae feed on stored legumes, nuts, cereals and other grains. Female beetles can lay up t0 400 eggs and live for approximately 6 to 8 months. The red…
P. ulmi is a major pest in almost all fruit growing regions of the world. The mites feed by puncturing cells of the leaf parenchyma with their stylets and sucking out their contents. This causes physiological changes in the leaves, and photosynthesis, transpiration and nitrogen accummulation can be severely constrained. Spread of P. ulmi to most apple-growing areas has probably been caused by the distribution of nursery stock carrying winter eggs. A wide host range includes deciduous bushes and trees…
The cowpea flower thrips or African bean flower thrips are shiny, black, slender, small-winged insects that feed on flower buds and flowers. During the pre-flowering period, nymphs and adults may damage the terminal buds. However, the main damage is on the flower buds and flowers. Attacked flower buds become brown and eventually fall off, leaving behind dark red scars. Damaged flowers are distorted and malformed. They change colour and may fall off early, with the result that pods are not…
…hatchet or meat cleaver. All tsetse fly are brown in colour and their palps, part of their mouth parts, always point forward, even when feeding, giving the impression of a long “snout”. Both female and male tsetse fly feed exclusively on blood. After mating the female stores the sperm which she uses to fertilize a single egg at a time. The fertilized egg hatches within the uterus, where the larva remains, feeding from a special gland. The female carries the…
Tobacco thrips (Frankliniella fusca) is a pest of a wide range of economically important plants, including field crops, vegetables, peanuts and ornamentals. Frankliniella fusca can reproduce sexually or parthenogenetically. The lifecycle is completed in 15-25 days, with development from egg, 2 larval stages, pre-pupa, pupae through to adult. Adult thrips are small (1-2mm) and are brown or black in colour. Adults and larvae feed on new plant growth, with high infestations causing damage through plant disfiguration or growth inhibition. Frankliniella…
M. aenus is an important pest of oilseed rape particularly in Western Europe. The larvae are up to 3 mm long and white with brown sclerotised plates. Eggs are laid in the flower buds of the host-plant and the larvae develop within the flowers. Oviposition damage to the buds of oilseed rape can cause the flowers to drop off. Both adults and larvae feed on the pollen and nectar in the flowers. Resistance to pyrethroids has been reported in this…
…mulch, or in cracks in support-stakes or under earth mounds. The larvae hatch after 4-15 days, and are initially very active, dispersing rapidly. Over a period of 3-4 weeks, they pass through five instars. In non-diapausing individuals (i.e. during the summer), the adult moth emerges 8-14 days after pupation. Towards the end of the season, mature larvae of the last generation leave the plant in search of a hibernation site, mostly under bark, in cracks of wooden support stakes or…