a t s In the state of Veracruz, Mexico, fruits from 38 sites at various altitudes were collected monthly over a period of 2 years, and the tephritid fruit flies of the genus Anastrepha and associated parasitoids that emerged rom these fruits were identified and counted. Of the 6 species of fruits that contained Anastrepha larvae, 18 species also contained a total of 10 species of Anastrepha par...

A two-component di€erential equation model is formulated for a host±parasitoid interaction. Transient dynamics and population crashes of this system are analysed using di€erential inequalities. Two di€erent cases can be distinguished: either the intrinsic growth rate of the host population is smaller than the maximum growth rate of the parasitoid or vice versa. In the latter case, the initial r...

The environmental compatibility of a biological control agent is an important aspect of successful reduction of agricultural pests. Temperature fluctuations during the day have a strong influence on the performance of laboratory-reared parasitoids. In field conditions, Trichogramma (Hymenoptera: Trichogrammatidae) wasps are exposed to variable temperatures during their development, which has a ...

In 1999, it was confirmed that Chilo sacchariphagus Bojer was attacking sugarcane at Açucareira de Moçambique, Mafambisse, and in 2001 from Companhia de Sena, Marromeu. In 2000, Açucareira de Moçambique requested that the South African Sugar Association Experiment Station investigate a classical biological control programme against this exotic borer using Xanthopimpla stemmator Thunberg. To thi...

Domestication of crop plants selects for numerous traits that often distinguish them dramatically from their wild progenitors. In some cases, these modifications lead to increased herbivory, by enhancing their attractiveness to herbivorous insects or reducing the efficiency of natural enemies, or both. This study investigated the effects of fruit enlargement on the olive (Olea europaea L.), the...

Parasitic wasps and flies (parasitoids) exert high mortality on caterpillars, and previous studies have demonstrated that most primary and secondary defenses do not protect caterpillars against parasitoids. We investigated the efficacy of tertiary defenses (i.e., immune responses) against parasitoids. Using a bead injection technique to measure the immune response and a 15-year database to meas...

The diamond back moth Plutella xylostella (L.) is the most serious pest of Brassicaceae in the world. It is resistant to many insecticides which has led to a search for alternative techniques of control, principally biocontrolbased pest management. The impact of P. xylostella and its parasitoids was analysed in a 6-month study of cabbage crops in the Brasilia region of Brazil, from June to Nove...

Population cycles of the winter moth (Operophtera brumata) in sub-arctic coastal birch forests show high spatiotemporal variation in amplitude. Peak larval densities range from levels causing little foliage damage to outbreaks causing spatially extensive defoliation. Moreover, outbreaks typically occur at or near the altitudinal treeline. It has been hypothesized that spatiotemporal variation i...

Developmental time, longevity, and lifetime fertility of three previously introduced parasitoids (Acerophagus papayae Noyes and Schauff, Anagyrus loecki Noyes and Menezes, and Pseudleptomastix mexicana Noyes and Schauff) (Hymenoptera: Encyrtidae) of the mealybug Paracoccus marginatus Williams and Granara de Willink (Hemiptera: Pseudococcidae) were studied in the laboratory to understand the ou...

Habitat fragmentation can disrupt communities of interacting species even if only some of the species are directly affected by fragmentation. For instance, if parasitoids disperse less well than their herbivorous hosts, habitat fragmentation may lead to higher herbivory in isolated plant patches due to the absence of the third trophic level. Community-level studies suggest that parasitoids tend...