The comments on climate and weather of the study area of the distribution of the populations of the Stag Beetle Lucanus cervus in the surroundings of Heidelberg and Mannheim include Mediterra-nean-like climate, immigration of meridional insects, average temperatures, maximum temperatu-res, wind and humidity.
5.1 Mediterranean-like climate
The middle and southern parts of the elongated plain of the Upper Rhine valley in the southwestern part of Germany are characterized by a Mediterranean-like climate with warm summers and mild winters which allows the growth and cultivation of peach, fig, kiwi and lemon trees and in some re-gions and/or in some extension even olive, orange and palm trees, and that supports also the wide-spread viticulture of red, blue, green and white grapes from which excellent and world-famous red and white wines and champagnes are produced. The peach trees that are cultivated in various gar-dens and orchards around Nußloch and Walldorf south of Heidelberg comprise different types with red, orange yellow, light yellow, yellowish green and greenish grey fruits and have been full of sweet and mature fruits in late summer 2009. Fig and kiwi trees are present in various gardens in the surroundings of Heidelberg where they produce fruits almost every year.
5.2 Immigration of meridional insects
The Mediterranean-like climate in the middle and southern parts of the Upper Rhine valley is also highlighted by the autochthonous occurrence of some typical thermophilous and heliophilous meri-dional insects such as the Praying Mantis Mantis religiosa LINNAEUS 1758 (Mantodea: Mantidae) which is particularly a characteristical member of the caloriphilous and solarophilous assemblage of the entomofauna of the Kaiserstuhl northwest of Freiburg (STROHM 1924, DETZEL 1992; BRECHTEL, EHRMANN & DETZEL 1996; DETZEL & EHRMANN 1998; EHRMANN 2002, 2003; STÄRZ 2006) which repre-sents the eroded remnants of an outstanding Tertiary volcanic complex having perforated and sitting on the fluvial sand plain, and that contains also other Mediterranean elements.
The Delta Mud wasp Delta unguiculatum (VILLERS 1789) (Hymenoptera: Eumenidae) which is also originally of meridional provenance has immigrated into the southern parts of Germany already more than 100 years ago and is established as a permanent resident with stable indigenous popula-tions in an extensive area in the Upper Rhine valley and in the side valleys in the adjacent highlands since long time (MADER 2000), and the Mud-Dauber Sceliphron destillatorium (ILLIGER 1807) (Hymenoptera: Sphecidae) has also already immigrated into some regions of the southern parts of Germany (MADER 2001).
Another spectacular meridional element of the entomofauna is the largest saturnid nocturnal butter-fly in Middle Europe, the Giant Peacock Moth or Large Emperor Moth Saturnia pyri SCHIFFERMÜL
-LER (DENIS & SCHIFFERMÜLLER 1775) (Lepidoptera: Saturniidae), which does not occur in indigenous populations in Germany, but is present in autochthonous populations in parts of Switzerland, Aus-tria, France and Czechia, and sometimes even a few individuals immigrate temporarily as visitors into the southern parts of Germany where they are occasionally discovered as single specimens (EBERT & RENNWALD 1994), with among others one individual having been detected in Stuttgart in 1880 (WARNECKE 1927), several individuals having been captured in Heidelberg in 1907 and earlier years (SCHEPP 1908, KNÖRZER 1909), a few individuals having been noticed in Groitzsch southsouth-west of Leipzig in 1930 (IRMSCHER 1930), several individuals having been found in Singen west-northwest of Konstanz at Lake Constance in 1931 (FUNK 1931), several individuals having been en-countered within and around Saarbrücken in the period of abt. 1950 – 1960 (WAGNER-ROLLINGER 1950, SCHMIDT-KOEHL 1973) as well as one individual having been captured near Saarbrücken on 26.06.1963 (DUTREUX in PELLES 1963, ALPHONSE PELLES in HARBICH & WITTSTADT 1964), one indivi-dual having been observed in Sankt Ingbert northeast of Saarbrücken on 13.07.1975 (P. HUBERTUS in SCHMIDT-KOEHL 1977), several individuals having occurred within and around Sarreguemines (for-merly Saargemünd) at the boundary between Germany and France since 1902 (MÜLLENBERGER
1906a, WARNECKE 1927, H. MÄRKER & P. SEILER in SCHMIDT-KOEHL 1977), and several individuals having been observed around Basel at the boundary between Germany and Switzerland in 1955 and earlier years (BOURGOGNE 1957). An experiment of artificial introduction of the Giant Peacock Moth or Large Emperor Moth Saturnia pyri has been carried out in Bad Windsheim southeast of Würz-burg in 1872 (JÄCKEL 1873).
Another outstanding meridional and african element of the entomofauna is the largest sphingid noc-turnal butterfly in Middle Europe, the Death´s-Head Hawk-Moth Acherontia atropos LINNAEUS 1758 (Lepidoptera: Sphingidae), which immigrates regularly from the Mediterranean region and from Africa into Middle Europe and occurs also in indigenous populations in the southern parts of Ger-many at least during the aestival generation (HARZ 1965, EBERT & RENNWALD 1994), with a particular abundant immigration having happened in 1956 (KOCH, WARNECKE, WITTSTADT & MAZZUCCO 1958), but is not a permanent resident. Other thermophilous and heliophilous meridional and pontian in-sects which immigrate into the southern parts of Germany are discussed among others by HUBER
(1916) and WARNECKE (1927).
5.3 Average temperatures
The temperatures in the study area in the surroundings of Heidelberg and Mannheim during the flight period of the Stag Beetle Lucanus cervus in May, June and July are mainly in the range bet-ween abt. 18 °C and abt. 32 °C during the day and betbet-ween abt. 15 °C and abt. 28 °C during the cre-puscular period in the evening between 20 hrs and 22 hrs Middle European summer time when usually only a weak wind is blowing or it is even calm. The temperature range depends on the seve-rity of the interruptions of longer periods of summerly sunny weather with occasional rainshowers and thunderstorms by shorter phases of cooler and wetter weather with lower temperatures, more rainfall and also more windy conditions. The temperature range depends also on the elevation of the localities above sea level and on the strength of the wind. The cumulative duration of sunshine in the middle and southern parts of the Upper Rhine valley exceeds 1,500 hrs per year and reaches sometimes even 2,000 hrs per year (ARMBORST 2008, RHEIN-NECKAR-ZEITUNG 2010).
5.4 Maximum temperatures
The maximum temperature at peak days of heat phases can reach in most cases up to 35 °C and in extreme cases even up to 38 °C particularly in the plain of the Upper Rhine valley, with usually only a few of such peak days occurring in May and June but in some years more peak days being developed in July and August. In most of the years, the maximum temperature reaches or exceeds 35 °C only at up to abt. 3 – 5 days, and in many years, the maximum temperature is above 30 °C only at up to abt. 10 – 20 days, whereas in especially hot summers, the maximum temperature could reach or exceed 35 °C at up to abt. 20 – 30 days and is above 30 °C at up to abt. 40 – 50 days. Parti-cularly hot summers with extended heat phases in July and August have happened in 1994 and 2003. In some average or normal years, the maximum temperature does even not reach or exceed 35 °C at all, and the maximum temperature is above 30 °C only at up to abt. 5 – 15 days. A detailed record of the temperature as well as comments on rainfall and wind during the flight period of the Stag Beetle Lucanus cervus at the location of Tairnbach during my almost daily observations from 01.06.2008 to 15.08.2008 are contained in my book (MADER 2009a).
5.5 Wind
The wind in the study area in the surroundings of Heidelberg and Mannheim during the flight pe-riod of the Stag Beetle Lucanus cervus in May, June and July is mainly blowing from west to east and only subordinately to accessorily also from east to west. At many days, particularly in the mor-ning and in the evemor-ning it is almost calm, whereas during the day, either a weak to moderate wind is blowing or it is also nearly calm. Stronger winds are predominantly or exclusively restricted to sig-nificant changes of weather with arrival and passage of rain and storm fronts in phases of unstable weather and low pressure, whereas they are absent or occur only exceptionally in periods of stable weather and high pressure.
5.6 Humidity
The humidity of the air is often high in the plain of the Upper Rhine valley, whereas it is usually low in the surrounding highlands, but occasionally also low humidity is established in the plain and high humidity is developed in the highlands. Particularly the days before the ends of longer periods of warm, dry and sunny weather which are terminated and separated by shorter phases of cool,
cloudy and rainy weather are quite sultry in the plain of the Upper Rhine valley, whereas the air is usually slightly to considerably drier in the adjacent highlands. Quite sultry conditions develop also in the front of advancing thunderstorms which frequently start to build up during the afternoon and burst out in the evening.