Thermal Requirements, Fertility, and Number of Generations of Neoleucinodes elegantalis (Guenée) (Lepidoptera: Crambidae)

Abstract

The small tomato borer Neoleucinodes elegantalis (Guenée) (Lepidoptera: Crambidae) is one of the major pests of solanaceous in Central and South America. Little is known about the role of temperature on the biological traits of this species. Development time of the immature stages and longevity and reproduction of adults of N. elegantalis at constant temperatures (15, 20, 25, 27, and 30 ± 1°C) were determined when larvae were fed on fruits of the tomato hybrid "Paronset." Neoleucinodes elegantalis completed its life cycle at temperatures between 15°C and 27°C, indicating that it can remain active throughout the year in the subtropical region of Brazil. The temperature threshold (T t) was 8.8°C for the egg stage and 7.7°C for the larval and pupal stages. The small tomato borer required 588.2 degrees-day for its full development. At 30°C, the eggs were infertile, indicating that temperatures above 27°C are deleterious to the fertilization/embryonic development of the studied population of N. elegantalis. The number of generations of N. elegantalis per year in the Brazilian subtropical region is lower than for populations developing in warmer tropical areas. A relationship was found between the number of generations and the increase in latitude.

Potential risk levels of invasive Neoleucinodes elegantalis (small tomato borer) in areas optimal for open‐field Solanum lycopersicum (tomato) cultivation in the present and under predicted climate change

“…Some hypotheses explain this as a result of an efficient system of border protection or a lack of host species for N. elegantalis . There is no evidence showing that N. elegantalis has diapause, and thus to maintain survival over time there is a need for host plants . In Central and South America, where its occurrence is high, there are 23 and 16 host species of N. elegantalis respectively .…”

“…There is no evidence showing that N. elegantalis has diapause, and thus to maintain survival over time there is a need for host plants. 31,46,47 In Central and South America, where its occurrence is high, there are 23 and 16 host species of N. elegantalis respectively. 77,78 Of these species, six are weed species, all with occurrence only in South America and four in Central America with high numbers of occurrences registered.…”

“…). These datasets were obtained from published literature and from the Global Biodiversity Information Facility …”

“…In CLIMEX, TTHS and THHS define the heat stress parameter and heat stress accumulation rate respectively. The embryonic development of N. elegantalis eggs does not occur above 30 °C . Thus, TTHS was set at 30 °C and THHS was set at 0.0007 week −1 for N. elegantalis .…”

“…The moisture parameters are denoted by SM0 (lowest threshold), SM1 (lower optimum moisture level), SM2 (upper optimum moisture level) and SM3 (upper moisture threshold). 29 Studies of thermal requirements for N. elegantalis indicate suitable temperature parameters as DV0 = 8.8 ∘ C and DV3 = 30 ∘ C. 46 In addition, a temperature range of between 15 and 27 ∘ C is regarded as being of high suitability for N. elegantalis population growth, 46 and thus DV1 and DV2 were set at 15 and 27 ∘ C respectively. N. elegantalis has a higher incidence in wet tropical regions ( Fig.…”