Biological Parameters, Phenology and Temperature Requirements of Halyomorpha halys (Hemiptera: Pentatomidae) in the Sub-Mediterranean Climate of Western Slovenia

Abstract

In the last decade, the invasive brown marmorated stink bug Halyomorpha halys, native to East Asia, has become one of the most serious pests for agricultural crops worldwide. First detected in Europe (in Switzerland), the insect is now widely found across the European continent and many Eurasian countries. Since its first appearance in Slovenia in 2017 it has caused considerable damage to fruit and vegetable production. Understanding the biology and behavior in the local environmental conditions is of key importance for an effective pest management. Knowledge of the voltinism of the species is crucial to anticipate critical phases of pest development and for adapting control measures that target the vulnerable life stages of the pest. A 3-year study (2019–2021) of H. halys biological parameters was performed outdoors in Nova Gorica (western Slovenia), confirming that in the sub-Mediterranean climate this pest has two overlapping generations per year. The net reproductive rates observed in the studied period indicate growing populations. The highest population growth was recorded in 2019, when the net reproductive rate of increase (R0) reached 14.84 for the summer generation and 5.64 for the overwintering generation. These findings match the current situation in Slovenia, where increasing populations of H. halys and severe crop damage have been observed since 2019.

The Preliminary Study on the Biology of An Invasive Species, Halyomorpha halys (Hemiptera: Pentatomidae) in Northwest Türkiye

“…On the other hand, it was observed that overwintering BMSB adults laid eggs until the end of August in this study, as well as in some other studies in Türkiye (unpublished). (Rot et al 2022) In all the studies mentioned, it was observed that the first-generation adults produced fewer egg masses compared to overwintering adults, similar to some other countries. According to some researches (Nielsen and Hamilton, 2009a;Nielsen et al 2016;Costi et al 2017), the adult stages of two generations may overlap in field.…”

“…While overall mortality of nymphs in the first generation was 22.97%, it was 90.24% in the second generation (Table 1). Similarly, Rot et al (2022) reported that the overall mortality rate in the first generation ranged between 25.07 and 78.57%, and that it ranged between 31 to 100% in the second generation. Haye et al (2014) and Costi et al (2017) reported that total mortality and mortality rates for nymphal stages demonstrated significant differences in the first and second generation, which is consistent with our findings (Tablo 1).…”

“…The total development time from egg to adult was found to be 47.85 days in the 1 st generation in outdoor conditions and 47.13 days at 25 ֯ C under laboratory conditions in this study (Table 2). Similarly, Rot et al (2022) determined it to be 55.89 days for the 1 st generation, and the longest development period was 81 days in the 2 nd generation in outdoor conditions. However, in this study, 28 pairs of BMSB produced only 3 egg masses, and the mortality of second generation nymphs was very high (90%).…”

“…Few numbers of eggs laid by the first-generation females can be explained by the decline in the proportion of females with fully developed ovaries as a result of the reduction in photoperiod (< 15-15.5 h) (Reznik et al 2022). Rot et al (2022) and Govidan and Hutchison (2020) pointed it out as the primary cause of the second generation's reduced fecundity and longer pre-oviposition period. On the other hand, Nielsen et al (2008) noted that the genetic variations of individuals in the geographic populations, rearing conditions, or the collection dates of the individuals which were used for the study could be attributed to the differences in the pre-oviposition period and fecundity.…”

“…Considering the BMSB's the minimum temperature threshold, which has yet to be determined in Turkey, the accumulation of degree days were calculated using the references to four possible thresholds (DD12, 12.5, 13, 13.5) as the shown in Table 3. Rot et al (2022) reported that development from egg to adult requires 530 DD for the first generation and 545 DD for the second generation in Slovenia, based on the minimum temperature threshold of 12.2 o C determined by Haye et al (2014). The egg-to-adult development in the US population was determined to be 538 DD using 14.14 °C as the threshold (Nielsen et al 2008) and 530 to 590 DD in the Caucasian population for the developmental threshold of 13.3 °C (Musolin et al 2019).…”