Zygaena loti, the slender Scotch burnet, is a moth of the family Zygaenidae. It is a diurnal moth characterized by a black body, light colored legs, and red spots on its wings. The caterpillars are a yellow-green color and usually molt out of dormancy in late February to early March. The larvae feed on plants from the family Fabaceae until they enter their pupal stage and mature into adults in May to early June. For mating, Zygaenidae exhibit a dual-partner finding strategy, where females use pheromones while assuming a calling position, and males exhibit a patrolling behavior where they utilize both vision and the olfactory receptors in their antennae to locate a potential mate. Although regionally endangered as their population is declining, Z. loti is found all across Europe, inhabiting areas rich in their desired food plants: lime-rich, and characterized by a hot and dry climate. The decreases in their population are likely due to factors such as habitat loss and fragmentation brought on by commercial agriculture and urbanization, as well as global climate change. There are few conservation programs currently focusing on Zygaena loti.
Subspecies
The following subspecies are recognized:
Zygaena loti loti (the nominate subspecies) Zygaena loti achilleae (Esper, 1780) Zygaena loti alpestris Burgeff, 1914 Zygaena loti arragonensis Staudinger, 1887 Zygaena loti avilensis Koch, 1948 Zygaena loti balcanica Reiss, 1922 Zygaena loti erythristica Tremewan & Manley, 1969 Zygaena loti failliei Dujardin, 1970 Zygaena loti hypochlora Dujardin, 1964 Zygaena loti janthina Boisduval, 1828 Zygaena loti ligustica Rocci, 1913 Zygaena loti macedonica Burgeff, 1926 Zygaena loti miniacea Oberthur, 1910 Zygaena loti osthelderi Burgeff, 1926 Zygaena loti praeclara Burgeff, 1926 Zygaena loti restricta Stauder, 1915 Zygaena loti scotica (Rowland-Brown, 1919) Zygaena loti tristis Oberthur, 1884 Zygaena loti wagneri Milliere, 1885 Zygaena loti zobeli Reiss, 1921
Description
Zygaena loti, also called the slender Scotch burnet moth, is a member of the butterfly and moth order Lepidoptera and the family Zygaenidae. While most moths are categorized as nocturnal, Zygaenidae moths are unique in that they are day-flying or diurnal moths. The Z. loti has also been described as highly sedentary. With a wingspan of 25-35mm, the slender Scotch burnet moth can be identified as having a relatively small black body, light colored legs, and a pair of black or light brown colored, rounded wings with red spots. This moth in particular displays a sexual dimorphism, in which the wings of females are scaled much lighter than their male conspecifics and they possess a double white ruff. Frontwings are grayish-blue in the males, yellow-gray in the females, with six red spots which partly flow together. The kidney-shaped spot at the tip of the forewings consists in fact of the fifth and sixth spots, which have grown together. The hindwings are red and have a black border.
This species is rather similar to Zygaena exulans, Zygaena filipendulae and Zygaena lonicerae.
The caterpillars can reach a length of about . They are olive-green or yellow-green, with two yellow and two black dots on each segment and short white hairs.
Life cycle
The life cycle of Zygaena loti has not been well observed, but from the available literature the following likely life cycle can be constructed. The moth is characterized as an early burnet with caterpillars molting out of diapause in late February to early March. The caterpillars hide during the day in moss layers or herbage containing small, short plants less than 6 cm tall. There they also construct or spin their cocoons (oval-shaped, dull dirty whitish color) to enter their pupal stage. later mature into adult moths in May to early June. As adults, their flight time is somewhere from late May to early August depending on eclosion. Since they are diurnal, they only fly during the day. After mating, females will lay their eggs on larval food plants, such as the ones listed below, and the resulting larvae will feed from approximately August to early May, overwintering once and sometimes twice in their larval diapaused state.
Food resources
For larvae, there are some contrasting findings, but all observed food plants that Z. loti caterpillars have been found on are from the family Fabaceae, such as Hippocrepis comosa, Lotus corniculatus, Securigera varia, and Onobrychis vicilfolia.
For adult moths, even less has been recorded about their diets. Males may nectar on milkworts and thyme, while females may nectar on the flowers of the plants they ate in their larval stage (those listed above).