The South American tomato pinworm, Tuta absoluta (Meyrick) has been introduced into new geographic areas, including the Mediterranean region, where i

Trichogramma achaeae Nagaraja and Nagarkatti (Hymenoptera: Trichogrammatidae) is currently used as biological control agent for several lepidopteran pests. Knowledge of thermal requirements is essential to optimize its rearing procedures and inundative releases. The biological characteristics and two-sex life table parameters of T. achaeae were determined at five constant temperatures (15, 20, 25, 30, and 35 °C) using Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs. T. achaeae was able to develop and survive from 15 °C to 30 °C, but not at 35 °C. Temperature significantly affected the preadult development time and adult longevity, decreasing when temperature increased from 15 °C to 30 °C. Temperature significantly altered the sex ratio, being female biased between 15 °C and 25 °C. Age-stage, two-sex life table analysis indicated that net reproductive rate (R₀) was highest at 20 °C. Both the intrinsic rate of increase (r) and finite rate of increase (λ) increased with increasing temperature, while the mean generation time (T) decreased significantly. In addition, functional response of T. achaeae was studied, being significantly affected by temperature and host egg density, displaying a Holling type-I at 15 °C and a Holling type-II at 25 °C. The relevance of these results is discussed for the use of T. achaeae as biological control agent.

Relationships between the omnivorous predator Nesidiocoris tenuis (Reuter) and the egg parasitoid Trichogramma achaeae Nagaraja and Nagarkatti were studied in the laboratory (no-choice and choice assays, and functional responses) and in a greenhouse experiment. Both natural enemies are utilized in the biological control of tomato pinworm on greenhouse-grown tomato crops. Three different food items were offered to the predator: nonparasitized prey, prey parasitized for less than 4 d by T. achaeae, and prey parasitized for more than 4 d by the parasitoid. There were significant differences in consumption of food types, with highest consumption for nonparasitized prey, followed by parasitized (4 d), both in no-choice and choice trials. At the same time, the predator causes a significant mortality in the prey (over 80%) regardless of previous parasitism, resulting in a very coincidental intraguild predation detrimental to the parasitoid. It has also been observed that there was a change in the functional response by the predator from Type II in presence of nonparasitized prey to Type I when there was a combination of parasitized and nonparasitized prey. This represents an increase of instantaneous search rate (a’) and a decrease of handling time (T_h), which indicates a change in feeding behavior on the two prey types. Under greenhouse conditions, the intraguild predation reduced the percentage of parasitism by T. achaeae in just over 20%. However, when both natural enemies were present, a better control of pest Tuta absoluta (Meyrick) was achieved than in the case of application of any of them alone.

Worldwide, the potato tuber moth (PTM), Phthorimaea operculella (Zeller), is one of the most severe pests affecting potato (Solanum tuberosum L.), whether in open-air crops or during tuber storage. This work examines the potential control of this pest by two species of predatory mites, Macrocheles robustulus (Berlese) and Blattisocius tarsalis (Berlese), on pest eggs under laboratory conditions. In the two first assays, the acceptance rate of the pest eggs was assessed for each predatory mite. Then, in a third assay, the functional response of B. tarsalis was studied. The results showed that Macrocheles robustulus did not prey on the pest eggs (number of eggs surviving = 4.33 ± 0.38), whereas B. tarsalis did (number of eggs surviving = 0.5 ± 0.5). Likewise, B. tarsalis showed a type II functional response when it killed the eggs. The results showed the potential use of Blattisocius tarsalis as a biological control agent of P. operculella in potato under storage conditions.

The South American tomato moth Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a pest species of great economic importance in tomatoes, both in greenhouses and in open-air crops. This importance has increased in recent years because it has been introduced in many countries in Europe, Africa, and Asia. Insecticides different active ingredients and biological control agents are being used in the control of this pest species. This implies the need to make both groups compatible within IPM programmes. Therefore, the objective of this work was to study the compatibility between different insecticides and the use of the egg parasitoid Trichogramma achaeae Nagaraja and Nagakartti (Hymenoptera: Trichogrammatidae). Three groups of trials were carried out under laboratory and greenhouse conditions. Ten insecticides with the following active ingredient were evaluated: abamectin, azadirachtin, Bacillus thuringiensis, chlorantraniliprole, emamectin, flubendiamide, indoxacarb, methomyl, spinosad, and spiromesifen. In the results, three groups of insecticides were established based on their compatibility with the use of biological control: The first group (abamectin, B. thurigiensis, flubendiamide, indoxacarb and spiromesifen) showed a high degree of compatibility with egg parasitoid releases. The second group (azadirachtin and chlorantraniliprole, and methomyl) presented compatibility problems. Finally, the last group (emamectin, methomyl, and spinosad) did not apper to be compatible. The results found will allow a better application of IPM programmes in tomato crops for the control of this pest species.

The potato tuber moth (PTM), Phthorimaea operculella, is the main potato pest in the world, having managed to adapt to a wide range of climatic conditions, and causing damage to stored tubers. The effectiveness of a biological control using the parasitoid Trichogramma cacaeciae and the predatory mite Blattisocius mali was evaluated in PTM under conditions that simulated those of tubers in storage. The number of adults found at the end of the trial was significantly higher in the control (181.75 ± 11.00 adults/container) than in treatments where B. mali (24.50 ± 7.22) or T. cacaeciae (102.00 ± 14.61) were released. The biological control’s effectiveness using the Abbot formula was 86.52% for the predator and 43.88% for the parasitoid. In addition, the PTM population data was fitted by logistic models, and the best fit was found for the simple logistic function. Using the data generated from these functions, the control efficiencies for the mite and the parasitoid were 94.85% and 73.77%, respectively. B. mali showed greater potential for being incorporated into integrated PTM management programs than T. cacaeciae. Based on logistic functions, a novel way of estimating the effectiveness of predators and parasitoids is also presented and discussed.