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Abstract

The objective of this study was to determine whether differences in hairiness of tomato plants affect the functional and numerical response of the predator Neoseiulus californicus McGregor attacking the two-spotted spider mite, Tetranychus urticae Koch. Two tomato hybrids with different density of glandular hairs were used. The functional response was measured by offering eggs and adults of T urticae at densities ranging from 4 to 64 items per tomato leaflet (surface ca. 6.3 cm2); eggs were offered to predator protonymphs and deutonymphs, adult spider mites to adult predators. The number of spider mites eaten as a function of initial density was fitted to the disc equation. Predator densities were regressed against initial prey densities to analyze the numerical response. The number of eggs and adults of T. urticae eaten by N. californicus was extremely low in both hybrids. The nymphal stage of N. californicus and prey density had a significant effect on the number of T urticae eggs eaten by the predator, while hybrid had no effect. The functional response fitted reasonably well to the Holling model. The handling time (Th) and the attack rate (a) were very similar among the two hybrids. The numerical response indicated that the absolute density of predators increased with changes in spider mite densities but the relative predator/prey density decreased in both hybrids. Tomato hairiness prevented N. californicus from exhibiting a strong numerical response and the predator functional response was much lower than observed in other host plants and other phytoseiids. This result shows the need to consider plant attributes as an essential and interactive component of biological control practices.

Assessing the augmentation of Amblydromalus limonicus with the supplementation of pollen, thread, and substrates to combat greenhouse whitefly populations

“…The hairy leaves prohibited the movement of A . limonicus , which reduced the availability of oviposition sites and foraging ability 48 , 53 – 55 .

Figure 5 The two different host plants utilised to test the effects of four different pollen, thread, and substrate treatments on the ability of Amblydromalus limonicus to control greenhouse whitefly ( Trialeurodes vaporariorum ).

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Temperature-Dependent Functional Response of Harmonia axyridis (Coleoptera: Coccinellidae) on the Eggs of Spodoptera litura (Lepidoptera: Noctuidae) in Laboratory

“…The assessment regarding natural enemy potential to suppress pest population is mainly carried out via evaluation of functional response, which depicts the interaction between prey density and predation capacity [ 26 , 27 , 28 ], enabling suitable choice of predator to be utilized in classical and augmentative biological control programs [ 29 , 30 ]. However, functional response may be regulated by a range of factors such as host plant of the prey [ 31 , 32 , 33 , 34 , 35 , 36 ], feeding behaviour and history [ 37 ], prey species [ 38 , 39 ], predator and its phenology [ 40 , 41 ] and temperature also [ 42 , 43 , 44 , 45 ]. In these, temperature is regarded as one of the most fundamental aspect, with ability to affect predator growth, development and foraging behaviour and thus the functional response [ 44 ].…”

Visual, vibratory, and olfactory cues affect interactions between the red spider mite Tetranychus evansi and its predator Phytoseiulus longipes

“…Glandular trichomes produced by the tomato plant of the genus Lycopersicon (old scientific name for tomato until 2005), exude anti-feeding or noxious substances that impact negatively on biocontrol agents (Kennedy 2003). For example, direct negative effects on the search pattern and residence time of Neoseiulus californicus (McGregor) due to glandular trichomes on S. lycopersicum have been reported (Cédola et al 2001;Kennedy 2003;Simmons and Gurr 2005). Furthermore, an indirect prey mediated effect from tomato has recently been demonstrated on N. californicus, probably due to the sequestration of toxic secondary metabolites from the plant by T. evansi (Koller et al 2007).…”